The Clinical Core Unit will provide support for three projects: Project 2 - Genetic variations in the innate immune response to Neisseria gononhoeae; Project 4 -The Altemative Complement Pathway (ACP) and Properdin in N. gonorrhoeae infection and Project 5 - Experimental and human protective immunity to N. gononhoeae infecfion. The core will recruit eligible subjects, collect and process serum specimens and cervico/lavage specimens from women and perfomn selected laboratory tests. The Clinical Core will: 1. Identify and enroll male subjects infected with N. gononhoeae and their female spread contacts. 2. Collect epidemiologic, clinical and laboratory data on female spread contacts at the Nanjing STD Clinic. 3. Collect, process and store gonococcal strains, blood and genital secrefions from women who are the sexpartners of a man wifii gonorrhea. 4. Perfonn PCR analysis for M. genitalium and 7. vaginalis and evaluate Gram's stains of vaginal secretions for BV (Nugent's criteria) to assess eligibility of female spread contacts to partidpate in a study of the role of naturally present vaccine antitrady (and blocking anfibody) in the acquisition of gonontiea. 5. Perform porin genotyping on gonococcal strains to validate transmission of like portypes between dually infected partners (Project 5). 6. Measure anfibody levels in blood, directed against candidate vaccine anfigens (2-1-L8 and 207 epitopes) and against the target (Rmp) of blocking antibodies in uninfected female spread contacts (Project 5). 7. Provide gonococcal strains and cervico/vaginal lavage specirr^ns from gononrhea infected female spread contacts (and uninfected contacts) to Project 2 for assessment of lipid A variations in sbains and for assessment of corresponding cytokine profiles in lavage specimens. 8. Provide cervico/vaginal lavage specimens to Project 4 to assess potential for ACP activation and the role of Properdin.